Biodegradable materials have been known in the art for a number of years. More particularly, in the literature of medical research relative to such materials, reference is made to the following biodegradable materials:
Processed sheep dermal collagen (PSDC), Hench's bioglass, surgical grade polyurethanes, fibrinogens, polyiminocarbonates, poly (L-lactic) acid (also known as polylactic acid), and polyglycolic acid,
Representative articles in the literature relative to the above are: "Structure and Property Relationships for Design of Polyiminocarbonates," by Pulapura, et al, Biomaterials, 1990 (119): 666-78, "Rate Controlled Drug Delivery Systems: Controlled Release versus Sustained Released" by Chien in Medical Progress Technology 1989, 15 (1-2): 11-14; and "Enzymatic Activity Toward Poly (L-Lactic) Acid Implants by Schakenraad, et al, Jour. Biomedical Materials Research, 1990 May, 24(5):529-45.
The earliest known reference to a biodegradable tissue implant is West German Patent No. 2,424,169 (1974) to Little.
Much publicity has attended the so-called Norplant elements employed as birth control means and, as such, the Norplant has become well known among contemporary biodegradable materials.
Accordingly, medical research has now established, beyond question, the value of subcutaneous, and other implantation of therapeutic and pharmacologic agents within a biodegradable carrier to facilitate the potentiation or concentration of the agent within cellular tissue at a location which will maximize its benefit to the patient. The present invention is accordingly concerned with an improvement in the form and structure of the biodegradable drug carrier to effect a physical attachment at an internal site Thereby, enhanced delivery of a necessary drug or nutrient can be accomplished at a tissue specific internal site, thereby reducing the need for systemic treatment.
The instant invention is an improvement of my above referenced inventions, which provides for a configuration of the biodegradable substrate into the form of a projectile for tissue-specific delivery by an endoscope, such as a laparoscope, bronchoscope and laryngoscope.